The sub’s improvements include a flush-mount 3.94-inch-deep enclosure that doesn't protrude several inches from the wall as its predecessor did. The upgrade also adds a long-throw 10-inch aluminum driver and a round steel back plate to replace a thick MDF back plate, making more room for the driver to reach full extension, the company said.

Performance is promoted as exceeding that of its predecessor. The SlimSub delivers maximum output of 109dB from 40Hz to 80Hz with bass extension of -6dB at 25 Hz. Performance “rivals” that of the company’s larger, 6-inch-deep InWall Bronze/6 sub, the company contended.

The SlimSub fits into the same cutout as the company’s other in-wall subs, allowing for retrofit opportunities. The SlimSub comes with all three types of Triad’s Acoustimesh grille (wide, narrow and frameless). Triad offers to custom paint the grilles at the factory.
The sub is shipping.